IMPORTANCE Acne is a common, multifactorial skin condition, and treatments with novel mechanisms have been elusive. OBJECTIVE To assess the safety and efficacy of clascoterone cream, 1%, a novel topical androgen receptor inhibitor, in 2 phase 3 randomized clinical trials (CB-03-01/25 and CB-03-01/26). DESIGN, SETTING, AND PARTICIPANTS Two identical, multicenter, randomized, vehicle-controlled, double-blind, phase 3 studies conducted from November 2015 to April 2018 evaluated the efficacy and safety of use of clascoterone cream, 1%, in males and nonpregnant females 9 years and older with moderate or severe facial acne as scored on the Investigator's Global Assessment scale. Participants were enrolled if they had 30 to 75 inflammatory lesions and 30 to 100 noninflammatory lesions. INTERVENTIONS Patients were randomized to treatment with clascoterone cream, 1%, or vehicle cream and applied approximately 1 g to the whole face twice daily for 12 weeks. MAIN OUTCOMES AND MEASURES Treatment success was defined as an Investigator's Global Assessment score of 0 (clear) or 1 (almost clear), and a 2-grade or greater improvement from baseline and absolute change from baseline in noninflammatory and inflammatory lesion counts at week 12. Safety measures included adverse event frequency and severity. RESULTS A total of 1440 patients were randomzied in 2 studies. In CB-03-01/25, 353 participants were randomized to treatment with clascoterone cream, 1% (median [range] age, 18.0 [10-58] years; 221 [62.6%] female), and 355 participants were randomized to treatment with vehicle cream (median [range] age, 18.0 [9-50] years; 215 (60.6%) female); in CB-03-01/26, 369 participants were randomized to treatment with clascoterone cream, 1% (median [range] age, 18.0 [10-50] years; 243 [65.9%] female), and 363 participants were randomized to treatment with vehicle cream (median [range] age, 18.0 [range, 11-42] years; 221 [60.9%] female). At week 12, treatment success rates in CB-03-01/25 and CB-03-01/26 with clascoterone cream, 1%, were 18.4% (point estimate, 2.3; 95% CI, 1.4-3.8; P < .001) and 20.3% (point estimate, 3.7; 95% CI, 2.2-6.3; P < .001) vs 9.0% and 6.5% with vehicle, respectively. At week 12, in both CB-03-01/25 and CB-03-01/26, treatment with clascoterone cream, 1%, resulted in a significant reduction in absolute noninflammatory lesions from baseline to −19.4 (point estimate difference, −6.4; 95% CI, −10.3 to −2.6; P < .001) and −19.4 (point estimate difference, −8.6; 95% CI, −12.3 to −4.9; P < .001) vs −13.0 and −10.8 with vehicle, respectively, as well as a reduction in inflammatory lesions from baseline to −19.3 (point estimate difference, −3.8; 95% CI, −6.4 to −1.3; P < .001) and −20.0 (point estimate difference, −7.4; 95% CI, −9.8 to −5.1; P < .001) vs −15.5 and −12.6 with vehicle, respectively. Adverse events rates were low and mostly mild; the predominant local skin reaction was trace or mild erythema. CONCLUSIONS AND RELEVANCE Use of clascoterone cream, 1%, for acne treatment appears to demonstrate favorable efficacy and...

Fetal alcohol syndrome (FAS) is characterized by growth retardation, mental deficiencies, and numerous craniofacial and neuronal anomalies; the type and severity of these defects may be related to the time and dose of maternal ethanol exposure. Ethanol administered during presomitic stages results in the typical FAS craniofacial phenotype and is accompanied by a loss of cranial neural crest cells (CNCCs) through ethanol-induced cell death. However, the stage-specific effects of ethanol on the CNCC population is unknown. We examined the effects of ethanol on CNCC populations by treating in ovo chick embryos with a single ethanol dose (0.43 mmol/egg) at various stages of CNCC development, and corresponding to the first 3-4 weeks of human gestation. Ethanol treatment induced cell death and reduced CNCC populations in patterns consistent with observed dysmorphologies of CNCC-derived cranial structures. The precise population affected was dependent on the timing of ethanol exposure. Treatment at gastrulation or neurulation induced cell death and losses of CNCC populations, particularly those in rostral positions, and resulted in more severe craniofacial defects. In contrast, treatment at early somitic stages (4-16 somites) induced cell death, primarily within caudal CNCC populations, but resulted in less severe craniofacial defects, suggesting an increased capacity for recovery. These results suggest that there are distinct developmental windows during which the CNCCs may be particularly susceptible to ethanol-induced cell death. We conclude that ethanol exposure seems to affect specific events adversely during neural crest development. The timing of embryonic ethanol exposure relative to CNCC development could account, in part, for the heterogenous craniofacial defects observed in FAS.

Fetal alcohol syndrome (FAS) is characterized by growth retardation, craniofacial malformations, and heart and neural defects; the cellular and molecular mechanism(s) responsible for ethanol's teratogenicity remains unknown. Although the phenotype suggests that prenatal ethanol exposure perturbs neural crest cell development, direct proof that these cells are an in utero target is still lacking. Previous research suggested that cranial neural crest cells are eliminated by ethanol-induced apoptosis. We tested this hypothesis using a chick embryo model of FAS. A single dose of ethanol, chosen to achieve a concentration of 35-42 mg/dl, was injected in ovo at gastrulation and resulted in growth retardation, craniofacial foreshortening, and disrupted hindbrain segmentation. Ethanol exposure enhanced cell death within areas populated by cranial neural crest cells, particularly in the hindbrain and craniofacial mesenchyme. In contrast, control embryos had limited cell death within these regions. Subsequent immunolabeling with neural crest cell-specific antibody revealed that ethanol treatment resulted in fewer neural crest cell numbers, whereas neural crest migration patterns were unaffected by ethanol. These results suggest that prenatal ethanol exposure leads to loss of cranial neural crest cells. Such a loss could result, in part, in the phenotype characteristic of FAS.

The ability of both acute and chronic ethanol exposures to elicit cell death within specific embryonic and adult tissues is believed to partly underlie ethanol's pathogenicity; however, the mechanism underlying this cell death is unknown. This study partially characterized the mechanism of ethanol-induced neural crest cell death in a chick embryo model of fetal alcohol syndrome. In situ DNA end-labeling demonstrated this cell death was apoptotic and occurred at embryonic ethanol levels as low as 42 mM. Regardless of the initial exposure time, this apoptosis always appeared at a distinct developmental time point simultaneous with the normal deletion of a cranial neural crest subset. This suggested that ethanol might act through aberrant activation of the endogenous death pathway; however, ethanol exposure failed to induce two components of this pathway, the homeotic transcription factor msx-2 and the growth factor bone morphogenetic protein 4. Both endogenous and ethanol-induced death were blocked by local application of an interleukin-1beta converting enzyme/CED-3 protease (caspase) inhibitor, showing that the two paths converge mechanistically and suggesting the potential to prevent this aspect of ethanol's teratogenicity. Ethanol exposure did not significantly alter cell proliferation within neural crest-populated regions, suggesting that susceptibility to ethanol-induced death did not involve exit from the cell cycle. Apoptotic deletion of cranial neural crest could partially explain the craniofacial deficits characteristic of the fetal alcohol syndrome.

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